Using a heated atomic force microscope tip, researchers have drawn nanoscale conductive patterns on insulating graphene oxide. This simple trick to control graphene oxide’s conductivity could pave the way for etching electronic circuits into the carbon material, an important advance toward high-speed, low-power, and potentially cheaper computer processors. Researchers at the Georgia Institute of Technology and the U.S. Naval Research Laboratory instead “write” such nanoribbons on a surface rather than cutting graphene.
The researchers start with a graphene oxide sheet, which doesn’t conduct electric current. When they pull an AFM tip heated to between 150 °C and 1060 °C across the sheet, oxygen atoms are shed at the spots that the tip touches. This leaves behind lines of almost-pure graphene that are 10,000 times more conductive than the surrounding graphene oxide.
The researchers wrote lines as narrow as 12 nanometers across and at speeds of up to 0.1 millimeters per second. The writing speed increased with temperature.
The researchers plan to make transistors using their technique, but they might need additional processing first, says Yanwu Zhu, a graphene researcher at the University of Texas at Austin. For one thing, they will have to find a way to remove graphene oxide remnants from the conductive ribbons.